YASKAWA iQpump Series Programming Manual page 73

Figure 1.67
It should be noted that the bias applied by the A2 analog input functions differently than the level set by the H3-03. If both biases are used
simultaneously they will sum together.
The level of the A1 analog input, as a percentage of the maximum input (either 10 Vdc or 20 mA), can be viewed by the U1-15 monitor.
The level of the A2 analog input, as a percentage of the maximum input, can be viewed by the U1-16 monitor.
The bias applied by setting H3-09 = "0: Frequency Bias," can be used in conjunction with the parameter bias H3-03. In that case the H3-
03 bias is applied first which changes the slope of the Speed Command vs. Terminal A1 Voltage graph. Then the level of the A2 analog
input is summed with the A1 analog input level, which in effect shifts the Speed Command vs. Terminal A1 Voltage graph upwards or
downwards but does not change the slope of the line.
Figure 1.68
Factory Default
Function: Aux Reference (Setting: 2)
In order for the A2 analog input to be used as the master Speed Command, parameter H3-09 must be set for Aux Reference (H3-09 = "2:
Aux Reference"). Once A2 is configured as an auxiliary reference, it can be selected as the master Speed Command by setting H3-13 =
"1: Main Fref TA2". If H3-09 = 2, terminal A2 analog input will become the speed command when a digital input programmed for Multi-
Step Ref 1 (H1-0x = 3) is selected by a contact closure.
Function: PI Feedback (Setting: B)
Configuring the A2 analog input as PI Feedback (H3-09 = "B: PI Feedback") is a requirement of setting the iQpump drive up for PI
operation. The A2 analog input is the only source for feedback for PI operation though the setpoint can come from a number of different
sources (refer to the section covering the PI parameters for more information regarding specifying the setpoint source. PI parameters are
listed in "b5 PI Function" on page 24).
Parameters H3-10 (Terminal A2 Gain) and H3-11 (Terminal A2 Bias) can be used to configure the A2 analog input to match the signal
from the Feedback Transmitter.
The U1-24 monitor (PI Feedback) can be used to check the PI Feedback level with the digital operator.
Function: Frequency Bias 2 (Setting: D)
By setting H3-09 = "D: Frequency Bias 2," the A2 analog input will serve as a bias signal to the A1 Speed Command. This setting
functions the same as a setting of H3-09=0: Frequency Bias.
YASKAWA TM.iQp.02 iQpump Drive Programming Manual
10%
Bias
1V
0V
Figure 66 Effect of Frequency Bias Function on Speed Command
H3-02
H3-03
10V
A1 Voltage
Figure 67 Frequency Bias Applied to Analog Speed Command
H3-02
A2 Input
Input
Terminal A1 Voltage
9V 10 V
A1 Voltage
10V
With H3-03 applied
H3-02
H3-03
10V
With both H3-03 and analog input bias
(H3-09=0) applied
A1 Voltage
73